After you accept the software license terms and click
Next, you come to the Microsoft Dynamics NAV 2009
Installer page. This page presents the following options:

Install Demo

When you click this option, Setup immediately begins copying
files. After this, you have no further interaction with Setup
except to click Close to exit Setup after it is finished
copying files.

The Demo Install is intended for users who want to try out the
features of Microsoft Dynamics NAV 2009. It is not intended as the
foundation for a production environment.

Choose an Installation Option

When you click this option, Setup moves to the Choose an
Installation Option page, where you select from a set of
predefined installation configurations. You can also modify any
configurations on this page.